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<title>无标题文档</title>
	<script>
		function change1()
		{
		 var wen= document.getElementById('wen637');
         wen.style.fontSize=30;
		}
	    function change2()
		{
		 var wen= document.getElementById('wen637');	
         wen.style.fontSize=20;
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	<h1>
		<?php
		echo '现在是'.date("Y年m月d日 H:i:s"); 
		?> 
	</h1>
	<h2>
	<span onClick="change1">大</span>
	<span onClick="change2()">中</span>
	<span onMouseOver="change3()">小</span>
	</h2>
	<div id="wen637"><p>637作业文本浏览大小测试</p></div>
	<h3>
	
	</h3>
		
</body>
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